THE EFFECTS OF ATROPINE AND OTHER ANTIMUSCARINICS MAY BE ENHANCED BY THE CONCOMITANT ADMINISTRATION OF OTHER DRUGS SUCH AS AMANTADINE, SOME ANTIHISTAMINES, PHENOTHIAZINE, ANTIPSYCHOTICS, SOME ANTIARRHYTHMICS LIKE QUINIDINE AND TRICYCLIC ANTIDEPRESSANTS. INHIBITION OF DRUG-METABOLISING ENZYMES BY MAOIS MAY POSSIBLY ENHANCE THE EFFECTS OF ANTIMUSCARINICS. ANTIMUSCARINICS AND PARASYMPATHOMIMETICS MAY COUNTERACT EACH OTHER EFFECTS.